Abstract: A method for transmitting and receiving uplink signals using an optimized rank 3 codebook is disclosed. The optimized rank 3 codebook includes 6 precoding matrix groups, each of which has 1 variable having an amplitude of 1. Preferably, the optimized 4Tx rank 3 codebook has 12 precoding matrix, two precoding matrixes are selected from each the above 6 precoding matrix groups considering chordal distance and the number of precoding matrix.

Abstract: A method and a transmitting station for transmitting data in a wireless local area network are discussed. The method according to an embodiment includes generating a physical layer convergence procedure (PLCP) protocol data unit (PPDU), the PPDU including a Very High Throughput Signal (VHT-SIG) field and a PLCP Service Data Unit (PSDU); and transmitting the PPDU to a receiving station. The VHT-SIG field includes a class type and identification information, the class type indicates that the PPDU is transmitted by an access point (AP) or a non-AP station, the identification information includes a partial identifier formed from a Basic Service Set Identifier (BSSID), and the partial identifier has a length shorter than a length of the BSSID.

Abstract: A method for transmitting a sounding reference signal in a MIMO wireless communication system and an apparatus therefor are disclosed. The method for transmitting sounding reference signals (SRSs) in a MIMO wireless communication system comprises receiving sounding reference signal parameters from a base station; receiving information of the number of sounding reference signals which will be transmitted at a transmission time instant from the base station; if a plurality of sounding reference signals are provided, generating the sounding reference signals corresponding to each of the plurality of antennas by using the sounding reference signal parameters; and transmitting the generated sounding reference signals to the base station through their corresponding antennas at a specific transmission instant.

Abstract: A method for transmitting data in a wireless local area network, and a device therefore are discussed. The method according to one embodiment includes generating, by a transmitter, a very high throughput (VHT)-SIG-A field; generating, by the transmitter, a VHT-SIG-B field by applying a single column vector; and transmitting, by the transmitter, a physical layer protocol data unit (PPDU) to a receiver, the PPDU including the VHT-SIG-A field and the VHT-SIG-B field. The single column vector is obtained from a number of spatial streams for the receiver.

Abstract: A method for generating a channel quality indicator (CQI) in a mobile communication system is presented. The method includes grouping a number of subcarriers to form at least one channel quality indicator subband for generating a channel quality indicator, and generating a channel quality indicator in each channel quality indicator subband, wherein a size of each channel quality indicator subband is dependent on a system bandwidth value and is an integer multiple of a downlink frequency resource unit size, wherein the downlink frequency resource unit size is prescribed according to the system bandwidth value.

Abstract: A method and terminal are described for allocating resources for transmitting a signal in a multiple-input multiple-output (MIMO) wireless communication system. An uplink signal is transmitted using L layers at a terminal in a multiple-input multiple-output (MIMO) wireless communication system. Modulation symbols are generated by modulating output bit sequences of an interleaver matrix by a unit of log2 Q bits, where Q is a modulation order. Each of the output bit sequences has a size of L·log2 Q bits. The modulation symbols are mapped to the L layers and transmitted by using the L layers. The output bit sequences are generated by reading out entries of the interleaver matrix, column by column.

Abstract: A method for efficiently transmitting and receiving control information through a Physical Downlink Control Channel (PDCCH) is provided. When a User Equipment (UE) receives control information through a PDCCH, the received control information is set to be decoded in units of search spaces, each having a specific start position in the specific subframe. Here, a modulo operation according to a predetermined first constant value (D) is performed on an input value to calculate a first result value, and a modulo operation according to a predetermined first variable value (C) corresponding to the number of candidate start positions that can be used as the specific start position is performed on the calculated first result value to calculate a second result value and an index position corresponding to the second result value is used as the specific start position. Transmitting control information in this manner enables a plurality of UEs to efficiently receive PDCCHs without collisions.

Abstract: A method for transmitting a sounding reference signal in a MIMO wireless communication system and an apparatus therefor are disclosed. The method for transmitting sounding reference signals (SRSs) in a MIMO wireless communication system comprises receiving sounding reference signal parameters from a base station; receiving information of the number of sounding reference signals which will be transmitted at a transmission time instant from the base station; if a plurality of sounding reference signals are provided, generating the sounding reference signals corresponding to each of the plurality of antennas by using the sounding reference signal parameters; and transmitting the generated sounding reference signals to the base station through their corresponding antennas at a specific transmission instant.

Abstract: A method of transmitting data in a wireless local area network; and a device therefore are discussed. The method according to one embodiment includes generating, by a transmitting station, a physical layer convergence procedure (PLCP) protocol data unit (PPDU), the PPDU including a signal field and a data field; and transmitting, by the transmitting station, the PPDU to the receiving station. The signal field includes a class type indicating whether a transmission type of the PPDU is an uplink transmission or a downlink transmission.

Abstract: A method and a radio apparatus for signal transmission in a Wireless Local Area Network (WLAN) system are discussed. The method according to an embodiment includes generating first and second very high throughput (VHT) fields including first and second control information, respectively; and transmitting a physical layer protocol data unit (PPDU) including the first and second VHT fields to at least one target station. The first VHT field includes an indicator indicating whether the PPDU is to be transmitted by using a single-user multiple input multiple output (SU-MIMO) scheme or a multi-user multiple input multiple output (MU-MIMO) scheme.

Abstract: A method is provided for transmitting data in a wireless local area network. A transmitter generates an encoded data unit by performing a channel coding to transmission data to be included in a data field of a physical layer protocol data unit (PPDU). The transmitter generates at least one spatial block by re-arranging the encoded data unit, and divides each spatial block of at least one spatial block into two frequency segments. A bandwidth of each frequency segment is half of a bandwidth of the each spatial block. The transmitter interleaves the two frequency segments to generate a first interleaved segment and a second interleaved segment, respectively, and generates first and second mapped sequences by respectively mapping the first and second interleaved segments into a signal constellation. The transmitter performs an Inverse Discrete Fourier Transform (IDFT) on the first and second mapped sequences to generate and transmit a transmission signal.

Abstract: A method for channel-coding information bits using a code generation matrix including 32 rows and A columns corresponding to length of the information bits includes, channel-coding the information bits having “A” length using basis sequences having 32-bit length corresponding to columns of the code generation matrix, and outputting the channel-coded result as an output sequence. If “A” is higher than 10, the code generation matrix is generated when (A-10) additional basis sequences were added as column-directional sequences to a first or second matrix. The first matrix is a TFCI code generation matrix composed of 32 rows and 10 columns used for TFCI coding. The second matrix is made when at least one of an inter-row location or an inter-column location of the first matrix was changed. The additional basis sequences satisfy a value 10 of a minimum Hamming distance.

Abstract: A method for efficiently transmitting and receiving control information through a Physical Downlink Control Channel (PDCCH) is provided. When a User Equipment (UE) receives control information through a PDCCH, the received control information is set to be decoded in units of search spaces, each having a specific start position in the specific subframe. Here, a modulo operation according to a predetermined first constant value (D) is performed on an input value to calculate a first result value, and a modulo operation according to a predetermined first variable value (C) corresponding to the number of candidate start positions that can be used as the specific start position is performed on the calculated first result value to calculate a second result value and an index position corresponding to the second result value is used as the specific start position. Transmitting control information in this manner enables a plurality of UEs to efficiently receive PDCCHs without collisions.

Abstract: A method for transmitting channel quality information based on a differential scheme is disclosed. When channel quality information of a predetermined number of sub-bands selected by a receiver in a frequency selective channel is transmitted, total average channel information is transmitted. Channel information of the selected sub-bands is transmitted as sub-band differential information associated with average channel information. In this case, the sub-band differential information may be denoted by a specific value contained in a differential-value range including only positive (+) values. If at least two channel quality information is transmitted by a MIMO system, channel quality information of one channel is transmitted, then channel quality information of the other channel is transmitted as spatial differential information. In this case, the spatial differential information is denoted by a specific value contained in a differential-value range asymmetrical on the basis of “0”.

Abstract: According to one embodiment, a method for a wireless local area includes: generating a medium access control (MAC) protocol data unit (MPDU) to be transmitted to a target station; generating a physical layer convergence procedure (PLCP) protocol data unit (PPDU) by attaching a PLCP preamble to the MPDU; selecting a transmission channel; and transmitting the PPDU to the target station over the transmission channel. Selecting the transmission channel includes: performing clear channel assessment (CCA) on a first channel to determine whether the first channel is idle; and only after it is determined that the first channel is idle, selecting the first channel and at least one idle second channel as the transmission channel. The PLCP preamble includes channel allocation information indicating a bandwidth of the transmission channel.

Abstract: A method of transmitting data in a wireless local area network is provided. The method includes the steps of: generating a data unit including a MAC (Medium Access Control) header and MSDU (MAC Service Data Unit), generating an encoded data unit by encoding the data unit, generating one or more spatial blocks by dividing the encoded data unit, dividing each of the one or more spatial block into a first block and a second block, generating a first interleaved block and a second interleaved block by interleaving the first block and the second block respectively, generating a first mapped sequence by mapping the first interleaved block into signal constellation, generating a second mapped sequence by mapping the second interleaved block into signal constellation, generating the transmission signal by performing IDFT (Inverse Discrete Fourier Transform) to the first mapped sequence and the second mapped sequence; and transmitting the transmission signal.

Abstract: A method of indicating destination stations, performed by an access point (AP), in a wireless local area network (WLAN) system supporting multi-user multiple input multiple output (MU-MIMO) is provided. The method includes transmitting a sounding request frame to the plurality of destination stations to transmit a sounding frame used for channel estimation between the AP and each destination station, receiving the sounding frame in response to the sounding frame request from each station, and transmitting a first data frame spatially multiplexed with respect to the plurality of destination stations by performing channel estimation on the basis of the sounding frame, wherein the sounding request frame comprises a group identifier (ID) indicating the plurality of destination stations.

Abstract: A method and apparatus for signal transmission in a Wireless Local Area Network (WLAN) system. The method according to one embodiment includes generating a first very high throughput (VHT) signal, generating a second VHT signal, and transmitting the first VHT signal and the second VHT signal. The first VHT signal includes an indicator indicating that the second VHT signal is to be transmitted by using a single-user multiple input multiple output (SU-MIMO) scheme or a multi-user multiple input multiple output (MU-MIMO) scheme. The first VHT signal and the second VHT signal are used to transmit control information, and the control information includes a modulation and coding scheme (MCS) index indicating an MCS used in the step of transmitting and further includes a spatial stream identifier indicating a number of spatial streams.

Abstract: A method of transmitting signals by a transmitting end in a wireless communication system comprises sharing control information related to reference signal with a receiving end; generating one or more precoded reference signals considering a given rank; allocating the one or more precoded reference signals to have a specific pattern within a subframe, wherein the specific pattern is varied depending on the control information; and transmitting the subframe through multiple antennas to the receiving end.

Abstract: A method for effectively transmitting/receiving a codeword in a MIMO system is disclosed. In a system including a plurality of predetermined rank structures, a reception end transmits rank information (RI), precoding matrix index (PMI), and channel quality information (CQI) of each codeword to a transmission end. The transmission end selects a rank structure on the basis of information received from the reception end. The transmission end selects only some codeword blocks among a plurality of codeword blocks available for the selected rank structure, transmits signals via the selected codeword blocks, and transmits a null signal for the non-selected codeword blocks.